Drug holiday as a prognostic factor of medication-related osteonecrosis of the jaw

Rat Calvaria Model Mimicking the Intraoral Lesion of Medication-Related Osteonecrosis in the Jaw: A Preliminary Test

Numerous preclinical intraoral models have been proposed to study medication-related osteonecrosis of the jaws (MRONJ). However, an extraoral animal model is necessary to investigate the effects of interventions such as grafts or direct therapeutics. This study aimed to establish a MRONJ rat model on the calvaria. Seven rats were allocated to either the control or MRONJ group. The MRONJ group received injections of zoledronic acid and dexamethasone to induce osteonecrosis over 4 weeks. Two weeks after these injections, the maxillary first molar was extracted, and two calvaria defects were created using a 4 mm trephine burr. One defect was left untreated, while the other was filled with harvested calvaria bone. A histological examination of all calvaria in the MRONJ group revealed avascular necrosis and the destruction of cortical bone. An independent t-test and Pearson's correlation coefficient were used for statistical analysis and the evaluation of alveolar and calvaria defects. The total alveolar and calvaria defect volume in the control group was significantly smaller than that in the MRONJ group. A statistically significant correlation was observed between alveolar and calvaria defects (Pearson correlation = 0.6, p = 0.023). The autogenous grafts showed poor results in the MRONJ group since they failed to revascularize and exhibited necrosis. The calvaria in this study successfully mimicked MRONJ lesions with avascular necrosis. This preclinical model could be used to develop treatments that are applicable to MRONJ.

Are medication-induced salivary changes the culprit of osteonecrosis of the jaw? A systematic review

Purpose

This systematic review was performed to assess the potential influence of medication-induced salivary changes on the development of medication-related osteonecrosis of the jaw (MRONJ).

Methods

An electronic search was conducted using PubMed, Web of Science, Cochrane, and Embase databases for articles published up to June 2023. A risk of bias assessment was performed according to the modified Newcastle-Ottawa Scale (NOS). Due to the heterogeneity of the selected studies in relation to the type of medications and outcomes evaluated, a meta-analysis could not be performed.

Results

The initial search revealed 765 studies. Only 10 articles were found to be eligible based on the inclusion criteria that reported on the impact of salivary changes on MRONJ following the administration of different medications. A total of 272 cases of MRONJ (35% women, 32% men, and 32% with no gender reported) with a mean age of 66 years at the time of diagnosis were included. Patients administered with bisphosphonates, steroids, chemotherapy, thalidomide, interferon, and hormone therapy had a significantly higher association between decreased salivary flow and MRONJ occurrence. In addition, bisphosphonates, denosumab, and other bone-modifying agents showed a significantly higher risk of developing MRONJ owing to the changes in salivary microbiome profiles, cytokine profiles, interleukins, hypotaurine, and binding proteins.

Conclusion

The reduction in salivary flow and changes in the concentration of salivary proteins were associated with the development of MRONJ. However, due to the availability of limited evidence, the findings of the review should be interpreted with caution.

Prospero review registration

https://www.crd.york.ac.uk/PROSPERO/, identifier: CRD42022327645.

Case series of medication-related osteonecrosis of the jaw (MRONJ) patients prescribed a drug holiday

The role of a drug holiday in the management of medication-related osteonecrosis of the jaw (MRONJ) remains controversial. Current UK guidance does not recommend this practice given the lack of conclusive evidence, and potential risk of skeletal-related events or cancer metastasis. This paper aims to describe a series of fifty patients with confirmed MRONJ who were prescribed a drug holiday as part of their management. Data were collected on exposures including: anti-resorptive and/or anti-angiogenic drug history, duration of drug, method of administration, concurrent therapy, MRONJ stage, management of MRONJ and duration of drug holiday. The primary outcome was complete healing as documented in the clinical notes. Multivariate Cox regression analysis was performed to evaluate the association between exposures and primary MRONJ outcome. Models were adjusted for age, sex, and index of multiple deprivation. Survival analysis was performed using a log-rank test, censoring any patients with no primary outcome recorded (p < 0.05). A total of 44% of patients stopped their medication for >36 months. Over half of all MRONJ cases presented in the posterior mandible and dental extraction was the most common precipitating factor (76%). Almost three-quarters (72%) of patients achieved complete healing. MRONJ recurrence (new site) was reported at 30%, mainly in those with incomplete healing of the initial area. There was a lack of evidence for an association between all recorded exposures and the primary MRONJ outcome using multivariate Cox regression. Similarly, we did not demonstrate evidence for an association between the duration of the drug holiday and MRONJ outcome. Our results support published guidelines, which do not recommend the discontinuation of bone modifying drugs for the prevention of MRONJ, or as part of treatment for established MRONJ.

The effect of drug holiday on preventing medication-related osteonecrosis of the jaw in osteoporotic rat model

Background

Medication-related osteonecrosis of the jaw (MRONJ) is a severe complication associated with antiresorptive medications managing osteoporosis, such as bisphosphonates (BPs). To date, there is very limited evidence from prospective, controlled studies to support or refute the controversial prevention regimen that if a discontinuation of BPs before dentoalveolar surgery, so called "drug holiday", is effective in reducing the risk of MRONJ development in patients with osteoporosis. We proposed an experimental animal study, aiming to investigate the prevention of MRONJ following tooth extractions in osteoporotic condition, with the implementation of a BP drug holiday.

Methods

Twenty rats were subjected to bilateral ovariectomy. After establishing the osteoporotic condition, all rats were exposed to weekly injections of zoledronate acid (ZA) for 8 weeks. After ZA treatment, 10 rats were subjected to dental extraction and defined as control group, and the rest 10 rats assigned to the DH group had a drug holiday of 8 weeks prior to dental extraction. Eight weeks after the dentoalveolar surgery, bone turnover biomarker in serum, occurrence of MRONJ-like lesion and histomorphometric assessment of osteonecrosis in mandible, and bone microarchitecture indices in femur, were examined.

Results

Eight weeks after dental extraction, the DH group showed a recovered osteoclastic activity, indicated by significantly increased number of osteoclasts in the mandibles and serum level of C-terminal telopeptides of type I collagen, as compared to the control group. No significant differences were observed in the gross-view and histological occurrences of MRONJ-like lesions between the two groups.There was no significant difference in bone microarchitecture in the femur between the control and DH groups before ZA therapy and 8 weeks after dental extraction.

Conclusion

Our data provided the first experimental evidence in the osteoporotic animal model that the implementation of a BP holiday in prior to dental extractions could partially recover osteoclastic activity, but could not alleviate the development of MRONJ-like lesion or exacerbate the osteoporotic condition in the femur. Longer-term drug holiday, or combination of drug holiday and other prophylaxes to prevent MRONJ in patients with osteoporosis could be worth exploring in future studies, to pave the way for clinical managements.

The translational potential of this article

This in vivo prospective study reported that a recovery of osteoclastic activity by a BP drug holiday for 8 weeks in osteoporosis rats did not alleviate the development of MRONJ-like lesion followed by dental extractions. It contributes to the understanding of regimens to prevent MRONJ.

Ineffectiveness of Antiresorptive Agent Drug Holidays in Osteoporosis Patients for Treatment of Medication-Related Osteonecrosis of the Jaw: Consideration from Immunohistological Observation of Osteoclast Suppression and Treatment Outcomes

In patients with osteoporosis receiving antiresorptive agents (ARs), it has been widely practiced to withdraw ARs for several months before tooth extraction and during treatment if medication-related osteonecrosis of the jaw (MRONJ) develops. This study examined the effects of drug holidays on recovery from osteoclast suppression and the treatment outcomes. The relationship between the period of the drug holidays and treatment outcomes was examined retrospectively in 166 osteoporosis patients with MRONJ who received ARs. Histological examinations using hematoxylin and eosin staining and cathepsin K stains were performed to observe the recovery from osteoclast suppression in 43 patients in whom living bone was observed in the resection margins of the surgical specimens. Three-month AR drug holidays were not significantly correlated with the treatment outcomes of the 139 patients who underwent surgical treatment and the 27 who underwent conservative treatment. Of the 43 patients who underwent histological investigations, 16 had drug holidays from 7 to 678 days. Osteoclast suppression was observed in almost all patients, except in one without a drug holiday and one with a 261-day drug holiday. These findings suggest that AR drug holidays for approximately 3 months neither recover osteoclast suppression nor affect treatment outcomes.

Relationship between drug holiday of the antiresorptive agents and surgical outcome of medication-related osteonecrosis of the jaw in osteoporosis patients

A drug holiday of 3 months does not promote separation of sequestra and is not correlated with treatment outcomes after surgical therapy in osteoporosis patients who receive antiresorptive agents and who have medication-related osteonecrosis of the jaw. Medication-related osteonecrosis of the jaw (MRONJ) is a serious adverse effect of antiresorptive agents alone or in combination with immune modulators or antiangiogenic medications, in the absence of radiation exposure to the head and neck region. The effectiveness of surgical treatment for MRONJ has been reported, but the timing of the operation remains controversial. The purpose of this study was to clarify whether preoperative drug holidays of antiresorptive agents promote sequestrum separation and improve treatment outcomes in patients who receive low doses of antiresorptive agents. This retrospective study included 173 patients who received low-dose antiresorptive agents and underwent surgical therapy. The effects of a drug holiday on the separation of sequestra and treatment outcomes were analyzed using logistic and Cox regression analyses. Multivariate analysis revealed that administration of an antiresorptive agent for more than 4 years, a high number of lymphocytes, and an extensive osteolytic area were significantly correlated with separation of sequestra, but drug holiday did not promote sequestrum separation. Furthermore, a drug holiday of 90, 120 or 180 days did not show any improvement in treatment outcomes. The drug holiday of the antiresorptive agents for the treatment of MRONJ is unnecessary, and surgical therapy should be performed early.

Medication-Related Osteonecrosis of the Jaw (MRONJ): A Review of Pathophysiology, Risk Factors, Preventive Measures and Treatment Strategies

Medication-related osteonecrosis of the jaw (MRONJ) is a major problem that can occur in people taking certain medications such bisphosphonates and denosumab. It can be used to treat osteoporosis or cancer. Bisphosphonate exposure, dental diseases and procedures, age, sex, anatomical factors, medical issues, and hereditary factors are all variables that enhance the risk of MRONJ. Even though MRONJ and antiresorptive medications have a close association, the pathophysiology of MRONJ is unknown. Careful dental preparation and oral hygiene instructions significantly minimize the risk of osteonecrosis of the jaw (ONJ). It is ideal to start antiresorptive treatment after the completion of required dental treatment; it is not contraindicated and carries low risk in patients who are on oral antiresorptive medications for less than three years. Drug holidays are one proposed solution to address MRONJ. However, there is still inadequate evidence to support their effectiveness. The objectives of this literature review are to recognize the main diagnostic principles and risk factors and to review the pathophysiology, protective procedures and treatment modalities related to MRONJ.

The following topics are covered in the review: epidemiology, diagnostic criteria, risk factors, pathogenesis and mechanism, MRONJ staging and symptoms, clinical and radiographic findings, treatment strategies, prevention and drug holiday.

Medication Related Osteonecrosis of the Jaw: 2021 Position Statement of the Korean Society for Bone and Mineral Research and the Korean Association of Oral and Maxillofacial Surgeons

Antiresorptives are the most widely prescribed drugs for the treatment of osteoporosis. They are also used in malignant bone metastases, multiple myeloma, and Paget's disease, and provide therapeutic efficacy on those diseases. However, it was reported that the occurrence of osteonecrosis of the jaw (ONJ) could be related to antiresorptive exposures, and there have been many cases regarding this issue. Therefore, a clearer definition and treatment guidelines were needed for this disease. The American Society for Bone and Mineral Research and the Amnerican Association of Oral and Maxillofacial Surgeons reported statements on bisphosphonate-related ONJ (BRONJ), and a revised version was recently presented. In the revised edition, the diagnosis BRONJ was changed to medication-related ONJ (MRONJ), which reflects consideration of the fact that ONJ also occurs for denosumab, a bone resorption inhibitor of the receptor activator of the nuclear factor-κB ligand antibody family, and bevacizumab, an anti-angiogenesis inhibitor. The Korean Society for Bone and Mineral Research and the Korean Association of Oral and Maxillofacial Surgeons had collectively formed a task force for the preparation of an official statement on MRONJ based on a previous position paper in 2015. The task force reviewed current knowledge and coordinated dental and medical opinions to propose the guideline customized for the local Korean situation.

Investigation of the Effectiveness of Surgical Treatment on Maxillary Medication-Related Osteonecrosis of the Jaw: A Literature Review

Aim: Medication-related osteonecrosis of the jaw (MRONJ) occurs after exposure to medication (antiresorptive or antiangiogenic agents) for bone-related complications. It is more common in the mandible than in the maxilla. The present study investigated maxillary MRONJ in elderly patients through a meta-analysis. Methods: Keywords, including “MRONJ”, “maxilla”, and “surgery”, were entered into databases, including Embase, PubMed/MEDLINE, Cochrane Library, and ProQuest, which were searched systematically. Results: Investigating 77 studies, we found that 18 (2 case reports and 16 case series) papers conformed to the standards. The results revealed a 2.6:1 female-to-male ratio of disease occurrence. The average age of patients was 70.6 ± 5.5 years, and most patients were in the third stage (43.6%). The average time of medication usage was 50.0 ± 20.1 months. The pooled proportion of clinical efficacy of surgery was 86%. Conclusion: To prevent and manage MRONJ, all elderly patients should maintain proper oral hygiene and receive dental examinations regularly. Risk assessment and safety management of MRONJ should be performed by medical teams.

A critical assessment of the medication-related osteonecrosis of the jaw classification in stage I patients: a retrospective analysis

Objectives

It is unclear whether the extent of intraoral mucosa defects in patients with medication-related osteonecrosis of the jaw indicates disease severity. Therefore, this study investigated whether mucosal lesions correlate with the true extent of osseous defects in stage I patients.

Materials and Methods

Retrospectively, all patients with stage I medication-related osteonecrosis of the jaw who underwent surgical treatment between April 2018 and April 2019 were enrolled. Preoperatively, the extent of their mucosal lesions was measured in clinical evaluations, and patients were assigned to either the visible or the probeable bone group. Intraoperatively, the extent of necrosis was measured manually and with fluorescence.

Results

Fifty-five patients (36 female, 19 male) with 86 lesions (46 visible bone, 40 probeable bone) were enrolled. Intraoperatively, the necrotic lesions were significantly larger (P<0.001) than the preoperative mucosal lesions in both groups. A significant (P<0.05) but very weak (R2<0.2) relationship was noted between the extent of the mucosal lesions and the necrotic bone area.

Conclusion

Preoperative mucosal defects (visible or probeable) in patients with medication-related osteonecrosis of the jaw do not indicate the extent of bone necrosis or disease severity.

Various Therapeutic Methods for the Treatment of Medication-Related Osteonecrosis of the Jaw (MRONJ) and Their Limitations: A Narrative Review on New Molecular and Cellular Therapeutic Approaches

Medication-related osteonecrosis of the jaw (MRONJ) is one of the most interesting diseases in the field of maxillofacial surgery. In addition to bisphosphonates, the use of antiresorptive and antiangiogenic agents is known to be the leading cause. However, the exact pathogenesis of MRONJ has not been established, and various hypotheses have been proposed, such as oxidative stress-related theory. As a result, a definitive treatment protocol for MRONJ has not been identified, while various therapeutic approaches are applied to manage patients with MRONJ. Although the surgical approach to treat osteomyelitis of the jaw has been proven to be most effective, there are limitations, such as recurrence and delayed healing. Many studies and clinical trials are being conducted to develop another effective therapeutic modality. The use of some materials, including platelet concentrates and bone morphogenetic proteins, showed a positive effect on MRONJ. Among them, teriparatide is currently the most promising material, and it has shown encouraging results when applied to patients with MRONJ. Furthermore, cell therapy using mesenchymal stem cells showed promising results, and it can be the new therapeutic approach for the treatment of MRONJ. This review presents various treatment methods for MRONJ and their limitations while investigating newly developed and researched molecular and cellular therapeutic approaches along with a literature review.

Apical surgery in cancer patients receiving high-dose antiresorptive medication-a retrospective clinical study with a mean follow-up of 13 months

PURPOSE

The aim of the study is to evaluate the results of apical surgery (AS) in patients receiving high-dose antiresorptive medication (HDAR).

METHODS

Retrospective descriptive quality control study conducted in an Oral and Maxillofacial Department at a University Hospital. Fourteen patients on HDAR met the inclusion criteria. Only descriptive statistics were applied.

RESULTS

Fourteen patients had operation on seventeen teeth. Mean HDAR treatment period before apical surgery: 25 months (SD, ± 24.27; range, 1-78 months). Drug holiday during surgery and initial healing: mean, 8 months (SD, ± 5.96; range, 0.4-22 months). Sixteen out of seventeen teeth healed clinically and showed complete or ongoing radiographic healing. All patients except one became free of symptoms. Mean follow-up: 13 months (SD, ± 9.05; range, 2-31 months). Radiographic healing according to Molven and Rud: 7, complete; 6, uncertain; 1, unsatisfactory. Three patients died during follow-up and were considered drop-outs.

CONCLUSIONS

The present case series suggest that apical surgery is a valid treatment option for apical periodontitis in patients on HDAR, where orthograde endodontic retreatment is not possible. None of the patients developed medication-related osteonecrosis of the jaw. Further studies in larger study groups and with longer follow-up periods are needed. The regional scientific ethical committee provided a document exemption, registration date 20 November 2013, and the local data protection agency approved handling of the recorded data (No. 2012-41-0045), registration date 11 January 2012.

Alendronate or Zoledronic acid do not impair wound healing after tooth extraction in postmenopausal women with osteoporosis

BACKGROUND

Bisphosphonates (BPs) are widely used for the prevention or treatment of osteoporosis. One of the most serious complications associated with BPs is medication-related osteonecrosis of the jaw (MRONJ) but its incidence in patients with osteoporosis is very low ranging from 0.001-0.15%. A major predisposing factor for MRONJ is tooth extraction (TE). Controversies persist about the influence of current BP therapy regarding socket healing after TE. The aims of this study were to investigate prospectively, (i) alveolar bone healing, i.e., filling of the bony socket by new bone and (ii) mucosal healing, i.e., closure of the overlying mucosa, after TE in women receiving current BP therapy for the prevention or the treatment of postmenopausal osteoporosis.

METHODS

Women with osteoporosis under current treatment with BPs (BP+ group) or other anti-osteoporotic medications (BP- group) undergoing single TE were included in this study. No antibiotic prophylaxis was prescribed solely for the BP therapy, but antibiotic treatment may have been required for local infectious conditions. Chlorohexidine mouthwashes were systematically prescribed in all study patients for one week after TE. New bone height (NBH) and rate of socket filling (RSF) were recorded using intraoral standardized radiographs one month and 3 months after TE (T30 and T90 respectively). The closure of the overlying mucosa was assessed by measuring the wound extent with an electronic caliper at 1 week and at 1 month after TE (T7 and T30 respectively).

RESULTS

At T30, NBH was not statistically different between the BP+ and BP- groups (p = .76). At T90, more than a two-fold in NBH increase was recorded for both groups with no statistically significant difference between them (p = .76). At T30 and T90, RSF was similar in both groups (p = .58 and p = .32 respectively). More than a two-fold RSF increase was founded between T30 and T90 in both groups. No demographic or BPs-related factors were correlated with the RSF at T90. At T7, the mucosa wound extent was reduced by more than two-fold with no statistically significant difference between both groups (p = .80). At this time, mucosa healing was achieved in 11.9% of the BP+ group and 10% of the BP- group (p = .99). At T30, mucosal healing was achieved in all patients but two, and at T90 it was achieved in all patients.

CONCLUSION

This study provides new insights into bone and mucosal healing in patients with osteoporosis taking BPs after TE. In this population, TE can be managed successfully with an appropriate surgical protocol and without discontinuation of BP treatment.

Efficacy of a high-dose antiresorptive drug holiday to reduce the risk of medication-related osteonecrosis of the jaw (MRONJ): A systematic review

A temporary discontinuation (drug holiday) of high-dose antiresorptive (AR) agents has been proposed to reduce the risk of medication-related osteonecrosis of the jaw (MRONJ). The aim of this systematic review was to answer the question: Is high-dose AR drug holiday, at the time of tooth extraction or dentoalveolar surgery, necessary to prevent the development of MRONJ in patients with cancer? This protocol was registered in the PROSPERO database. Medline, Embase, and the Cochrane Central Register of Controlled Trials (CENTRAL) were searched for relevant studies up to and including April 2019. Randomized controlled trials (RCTs), cohort and cross-sectional studies, surveys, and case reports with more than five patients were included. Records were imported into www.covidence.org. Electronic searches were supplemented by manual searches and reference linkage. The Preferred Reporting Items for Systematic Reviews and Meta Analysis (PRISMA) were followed. Although only one study fitted the population, intervention, comparison, outcome (PICO) framework, valuable information on AR drug holiday could be extracted from 14 of 371 reviewed articles. Among these, 3 were prospective and 11 were retrospective studies. These studies described or evaluated high-dose AR drug holidays. In 2 studies, patients were being treated with denosumab, but neither showed that a drug holiday was effective. The remaining 12 studies evaluated bisphosphonate treatment and 2 of these studies found no reason to use AR drug holiday before surgery. Three studies recommended drug holidays, whereas most of the studies recommended assessing each patient separately. The only paper that fitted the PICO approach was a non-randomized, prospective study with a control group. This study concluded that drug holiday was not necessary. Thus, there are no evidence for using drug holiday, but it is also clear that caused by a limited numbers of eligible patients, and a great variation in between these patient, high-level evidence for using AR drug holiday is almost impossible to obtain.

Drug holiday clinical relevance verification for antiresorptive agents in medication-related osteonecrosis cases of the jaw

Treatment strategies of medication-related osteonecrosis of the jaw (MRONJ) are controversial. Recently, surgical treatment has been reported as superior to nonsurgical treatment, but the contribution discontinued antiresorptive agent use during MRONJ treatment remains unclear. This study aimed to evaluate the efficacy of drug holidays and treatment strategies in MRONJ cases. Four-hundred and twenty-seven patients with MRONJ treated at nine hospitals from 2009 to 2017 were included in this multicenter retrospective study. Multivariate Cox regression analysis showed that the primary disease (osteoporosis or malignant tumor), diabetes, serum albumin, and treatment method (surgical or nonsurgical) were significantly correlated with the cure rate. The cumulative 1-year cure rates in the surgical and nonsurgical treatment groups were 64.7% and 18.2%, respectively. However, discontinuing antiresorptive agents did not influence the treatment outcome in the cohort overall, or in 230 patients after performing propensity score matching among the discontinuation and continuation groups. When stratifying by treatment method, antiresorptive agent discontinuation significantly increased the cure rate in patients with osteoporosis who underwent nonsurgical treatment. In patients with malignant tumors undergoing nonsurgical therapy, discontinuing the antiresorptive agent was associated with a better treatment outcome, but not with statistical significance. In contrast, drug holidays showed no effect on improving outcomes in patients with both osteoporosis and malignant tumors who underwent surgical therapy. Thus, regardless of the primary disease, discontinuing antiresorptive agents during treatment for MRONJ may not be necessary and may be helpful in some cases. Future prospective trials should examine this question further.

Value of pre-operative CTX serum levels in the prediction of medication-related osteonecrosis of the jaw (MRONJ): a retrospective clinical study

OBJECTIVES

The low incidence yet severe presentation of medication-related osteonecrosis of the jaw (MRONJ) makes it necessary to develop reliable predictive and preventive strategies. This study explored the value of pre-operative carboxy-terminal collagen crosslinks (CTX) serum level in the prediction of osteonecrosis-related complications in patients on bisphosphonate therapy.

PATIENTS AND METHODS

We examined patient records over 4 years (a total of 137 patients). Biometric data were extracted, in addition to type of treatment, CTX levels, drug holiday, procedure, complications, and co-morbidities. Non-parametric Wilcoxon two-sample tests were used to test the effect of initial CTX level in IV or PO and whether it was predictive of complications. Two independent proportion tests were used for testing the two different complication incident rates before or after the drug holiday.

RESULTS

A total of 93 patients were included in the study, of whom 88.17% were female. A total of 11 patients were receiving IV bisphosphonates at the time of initial presentation, 82 oral bisphosphonates. Out of 64 patients who underwent invasive dental procedure (IDP) before a drug holiday, eight were on IV bisphosphonates. Three patients in this group experienced osteonecrosis-related complications (37.5%). Out of the remaining 56 patients on oral bisphosphonates, four (7.14%) developed complications, significantly lower than the IV bisphosphonate group (p = 0.0364). On the other hand, of the 34 patients placed on a drug holiday prior to IDP, only one subject developed complications related to osteonecrosis. Five subjects who had operations both before and after drug holiday did not experience any complications. No statistical difference was detected in complication rates based on initial CTX level (above versus below 150 pg/ml), gender, comorbidities, or total duration of bisphosphonate treatment (p = 0.2675). The sensitivity and specificity of CTX cutoff of 150 pg/ml in predicting osteonecrosis were 37.5% and 57.7, respectively.

CONCLUSIONS

Serum levels of CTX by itself are not reliable as a predictive or preventive measure for such complications. Our data also suggested that a drug holiday of 5 months was not helpful in preventing osteonecrosis-related complications in patients on intravenous bisphosphonates. Further studies are urgently needed to develop adequate predictive and preventive strategies of MRONJ.

Medication related osteonecrosis of the jaws associated with targeted therapy as monotherapy and in combination with antiresorptives. A report of 7 cases from the Copenhagen Cohort

OBJECTIVE

The aim of this study was to report cases of medication-related osteonecrosis of the jaws (MRONJ) associated with targeted therapy (TT) with or without concomitant antiresorptive treatment, among the Copenhagen ONJ cohort, which includes all consecutive cases of MRONJ seen in Copenhagen.

STUDY DESIGN

We retrospectively studied the treatment of 204 consecutive patients with MRONJ, seen between January 2010 and May 2016, to identify those associated with TT.

RESULTS

We detected 7 cases of MRONJ associated with TT (3.4%). Four patients received TT only, whereas 3 were concomitantly treated with bisphosphonates (n = 3) and/or denosumab (n = 3). The TT regimens included sunitinib (Sutent) (n = 1), everolimus (Afinitor) (n = 1), erlotinib (Tarceva) (n = 1), bevacizumab (Avastin) (n = 3), dasatinib (Sprycel) (n = 1) and imatinib (Glivec) (n = 1). The MRONJ stage included stages 1 and 2, and mean score on the visual analogue scale for pain in the jaw was 4.0.

CONCLUSIONS

Health care providers should be aware of the possibility of MRONJ associated with the TT agents sunitinib, everolimus, and dasatinib and uncommon cancer types, including renal cell carcinoma, non-small-cell lung cancer, glioblastoma, and leukemia, where MRONJ may also occur.

Antiresorptive treatment-associated ONJ

Osteonecrosis of the jaw (ONJ) is a severe complication of therapy with antiresorptive agents (e.g. bisphosphonates and denosumab), which are used to manage bone metastases from cancer, to reduce the incidence of skeletal-related events. Available data indicate that 0-27, 5% of patients exposed to antiresorptive agents may develop ONJ, depending on the number of infusions and the duration of therapy. Besides antiresorptive therapy, a number of risk factors for osteonecrosis have been identified. Oral surgical procedures, tooth extractions and infection to the jawbones are considered the main risk factors for developing ONJ, when receiving antiresorptive therapy. However, a growing number of patients develop ONJ without apparent risk factors, raising concern for other predisposing factors. Jaw bone necrosis may be irreversible, resulting in a chronic disease with negative impact on the quality of patients' lives. The role of risk reduction strategies like meticulous dental screening and optimal oral hygiene is fundamental for preventing development of ONJ. ONJ is usually treated conservatively to relieve the symptoms and manage jaw bone necrosis. In certain cases, surgical intervention is required. Future research should emphasize individual predisposition to ONJ, more effective preventive measures and more efficient therapeutic procedures.

Effectiveness of treatments for medication-related osteonecrosis of the jaw: A systematic review and meta-analysis

BACKGROUND

The effectiveness of management strategies used for the treatment of medication-related osteonecrosis of the jaw (MRONJ) remains poorly understood. The authors evaluated systematically the effectiveness of the various treatment modalities used for MRONJ.

TYPES OF STUDIES REVIEWED

The authors conducted a comprehensive search of MEDLINE, Embase, the Cochrane Library, and Scopus to identify randomized controlled trials, nonrandomized controlled trials, and prospective cohort studies to evaluate comparatively the effectiveness of management strategies for the treatment of MRONJ. The authors conducted the identification of eligible studies in duplicate and synthesized the extracted data by means of a meta-analysis, when feasible.

RESULTS

The authors found 13 studies with a medium-to-high risk of bias that met the inclusion criteria of this review. The authors found that, compared with medical treatment of local antimicrobials with or without systemic antimicrobials, the study investigators associated surgical treatment with higher odds of complete resolution of the condition (2 studies; 76 participants; unadjusted odds ratio, 3.55; 95% confidence interval, 1.12 to 11.19). The effectiveness of other therapies, such as bisphosphonate drug holidays, teriparatide, and hyperbaric oxygen, was uncertain.

CONCLUSIONS AND PRACTICAL IMPLICATIONS

On the basis of the results of an unadjusted analysis, the results of the studies that were deemed to be medium to low quality and to have medium-to-low statistical power suggested that there are higher odds of resolving MRONJ with surgical treatment compared with medical treatment. High-quality research is required for conclusive statements to be made regarding treatment strategies for management of MRONJ.

Impact of communication between physicians and dentists on the incidence of jaw osteonecrosis caused by bone anti-resorptives

Dental management of osteoporosis patients on anti-resorptive therapy can be challenging for both the dentist and physician because of the risk of osteonecrosis of the jaw (ONJ). This editorial reflects on the paper written by Tagushi et al that expressed a relative lack of communication between health care providers when treating osteoporosis patients. Osteoporosis-related bone fractures can be debilitating and occasionally lethal, but management with anti-resorptives is vital while cognizant of the complication of ONJ that can also negatively impact patient’s quality of life.

Medication Related Osteonecrosis of the Jaw: 2015 Position Statement of the Korean Society for Bone and Mineral Research and the Korean Association of Oral and Maxillofacial Surgeons

Bisphosphonates are the most widely prescribed drugs for the treatment of osteoporosis, and are also used in malignant bone metastases, multiple myeloma, and Paget's disease, and provide therapeutic efficacy on those diseases. However, it was reported that occurrence of osteonecrosis of the jaw (ONJ) could be related with bisphosphonate exposures, and there have been many cases regarding this issue. Therefore, a clearer definition and treatment guidelines were needed for this disease. The American Society for Bone and Mineral Research (ASBMR) and American Association of Oral and Maxillofacial Surgeons (AAOMS) reported statements on bisphosphonate-related ONJ (BRONJ), and a revised version was recently presented. In the revised edition, the diagnosis BRONJ was changed to medication-related ONJ (MRONJ), which reflects a consideration of the fact that ONJ also occurs for denosumab, a bone resorption inhibitor of the receptor activator of nuclear factor-kappa B ligand (RANKL) antibody family, and bevacizumab, an anti-angiogenesis inhibitor. In 2009, a statement on ONJ was also reported locally by a relevant organization, which has served as basis for clinical treatment in Korea. In addition to the new official stance of the AAOMS and ASBMR, with an increasing pool of ONJ clinical experience, a revised version of the 2009 local statement is needed. As such, the Korean Society for Bone and Mineral Research (KSBMR) and the Korean Association of Oral and Maxillofacial Surgeons (KAOMS) have collectively formed a committee for the preparation of an official statement on MRONJ, and have reviewed recent local and international data to propose guidelines customized for the local Korean situation.

Perioperative discontinuation of intravenous bisphosphonate therapy reduces the incidence and severity of bisphosphonate-related osteonecrosis of the jaw: A randomized, controlled, prospective experimental study in rats

OBJECTIVE

To evaluate the effects of intravenous bisphosphonate discontinuation on incidence and severity of bisphosphonate-related osteonecrosis of the jaw (BRONJ).

MATERIAL AND METHODS

Seventy rats were randomly divided into 7 groups. In control and S0 groups, weekly injection of saline and 0.06 mg/kg zoledronate (respectively) for 4 weeks, tooth extraction, continuation of injections for 2 months and euthanasia were performed. In group S1, zolendronate injection for 4 weeks, tooth extraction, zolendronate discontinuation for 2 months, and euthanasia were done. For groups S2, S3, S4, and S5, zolendronate injections for 4 weeks, drug holiday for 1-4 months (respectively) before and 2 months after tooth extraction, and euthanasia were performed. Presence of bone exposure, osteonecrosis, and new bone formation were clinically and histologically evaluated.

RESULTS

The rate of BRONJ in control, S0, S1, S2, S3, S4, and S5 groups was 0%, 85%, 80%, 65%, 60%, 50%, and 40%, respectively. In control group, epithelial healing, bone formation, and absence of osteonecrosis; and in S0 group, unhealed epithelium, osteonecrosis, and impaired bone formation were histologically observed. In study groups, prolongation of drug holiday caused diminished osteonecrosis, and improved bone and epithelial healing.

CONCLUSION

Zolendronate discontinuation significantly decreased the incidence and severity of BRONJ in rats.